Re: [RFC][PATCH v2 4/5] dt-bindings: usb: dwc3: of-simple: add compatible for HiSi

[John Stultz]

On Mon, Oct 7, 2019 at 11:38 AM Rob Herring <robh+dt@xxxxxxxxxx> wrote:
>
> On Mon, Oct 7, 2019 at 12:56 PM John Stultz <john.stultz@xxxxxxxxxx> wrote:
> >
> > Add necessary compatible flag for HiSi's DWC3 so
> > dwc3-of-simple will probe.
> >
> > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> > Cc: Felipe Balbi <balbi@xxxxxxxxxx>
> > Cc: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
> > Cc: Rob Herring <robh+dt@xxxxxxxxxx>
> > Cc: Mark Rutland <mark.rutland@xxxxxxx>
> > Cc: Yu Chen <chenyu56@xxxxxxxxxx>
> > Cc: Matthias Brugger <matthias.bgg@xxxxxxxxx>
> > Cc: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
> > Cc: linux-usb@xxxxxxxxxxxxxxx
> > Cc: devicetree@xxxxxxxxxxxxxxx
> > Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
> > ---
> > v2: Tweaked clock names as clk_usb3phy_ref didn't seem right.
> > ---
> >  .../devicetree/bindings/usb/hisi,dwc3.txt     | 52 +++++++++++++++++++
> >  1 file changed, 52 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/usb/hisi,dwc3.txt
>
> Can you make this a schema.

Sorry, I'm not sure exactly what you're asking. I'm guessing from
grepping around you want the bindings in yaml instead (I see a few
examples)? Is there some pointer to documentation? The
Documentation/devicetree/bindings/writing-bindings.txt file doesn't
seem to say much on it.

> > diff --git a/Documentation/devicetree/bindings/usb/hisi,dwc3.txt b/Documentation/devicetree/bindings/usb/hisi,dwc3.txt
> > new file mode 100644
> > index 000000000000..3a3e5c320f2a
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/usb/hisi,dwc3.txt
> > @@ -0,0 +1,52 @@
> > +HiSi SuperSpeed DWC3 USB SoC controller
> > +
> > +Required properties:
> > +- compatible:          should contain "hisilicon,hi3660-dwc3" for HiSi SoC
> > +- clocks:              A list of phandle + clock-specifier pairs for the
> > +                       clocks listed in clock-names
> > +- clock-names:         Should contain the following:
> > +  "clk_abb_usb"                USB reference clk
> > +  "aclk_usb3otg"       USB3 OTG aclk
> > +
> > +- assigned-clocks:     Should be:
> > +                               HI3660_ACLK_GATE_USB3OTG
> > +- assigned-clock-rates: Should be:
> > +                               229Mhz (229000000) for HI3660_ACLK_GATE_USB3OTG
> > +
> > +Optional properties:
> > +- resets:              Phandle to reset control that resets core and wrapper.
>
> Looks like 4 resets though.

Good point. I'll fix that up.

> > +
> > +Required child node:
> > +A child node must exist to represent the core DWC3 IP block. The name of
> > +the node is not important. The content of the node is defined in dwc3.txt.
> > +
> > +Example device nodes:
> > +
> > +       usb3: hisi_dwc3 {
> > +               compatible = "hisilicon,hi3660-dwc3";
> > +               #address-cells = <2>;
> > +               #size-cells = <2>;
> > +               ranges;
> > +
> > +               clocks = <&crg_ctrl HI3660_CLK_ABB_USB>,
> > +                        <&crg_ctrl HI3660_ACLK_GATE_USB3OTG>;
> > +               clock-names = "clk_abb_usb", "aclk_usb3otg";
> > +
> > +               assigned-clocks = <&crg_ctrl HI3660_ACLK_GATE_USB3OTG>;
> > +               assigned-clock-rates = <229 000 000>;
> > +               resets = <&crg_rst 0x90 8>,
> > +                        <&crg_rst 0x90 7>,
> > +                        <&crg_rst 0x90 6>,
> > +                        <&crg_rst 0x90 5>;
> > +
> > +               dwc3: dwc3@ff100000 {
>
> If it's only clocks and resets for the wrapper node, just make this
> all one node.

Just to make sure I'm following, you're suggesting I put all the
clocks/resets in the dwc3 node (renamed to usb for the node name) and
not add the wrapper?

I'll have to see if that's possible. The generic dwc3 binding wants 3
clocks, but I only have two in the code I've worked with (similarly it
seems to only want two resets, not 4) so I'll have to see if I can
figure out how to adapt that.

If that approach is preferred, do I also no longer need a separate
binding document/schema?

thanks
-john